• 한국기계가공학회지
• /
• 제4권1호
• /
• pp.37-42
• /
• 2005

The localization of manufacturing technique development is actualizing for low cost with supplies of display devices. We need more high cutting technique because consumers want flat glasses of various sizes. Recently, most general two methods are normal wheel cutting and laser cutting, but both of them have some faults. First, the wheel cutting has cracks and sharp edges of sections. Second, it is easy for laser cutting to cut curved lines. however, it has thermal damage and low traverse speed. I suggest a new cutting method by high-wave frequency vibration wheel cutting(HFVC), which is good for quality improvement. Vertical cracks and crack depth is observed, after HFVC. When the average of the crack depth is $30{\mu}m$ and the average of the wallner liner depth is $200{\mu}m$, it has the most high quality of the sections in this experiment. As a result, when we consider between the normal wheel cutting method and the HFVC method, the latter has low cracks and good quality.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.325-332
• /
• 2006

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation, because the material property has strong axial stiffness, but little bending stiffness. The problem of cutting pattern is highly varied in their size, curvature and material stiffness. So, the approximation inherent in cutting pattern generation methods is quite different. Therefore the ordinary computer software of structural analysis & design is not suitable for membrane structures. In this study, we develop the program for cutting pattern generation using geodesic line, and investigate the result of example's cutting pattern in detail.

• 한국공간구조학회:학술대회논문집
• /
• 한국공간구조학회 2006년도 춘계 학술발표회 논문집 제3권1호(통권3호)
• /
• pp.205-213
• /
• 2006

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation, because the material property has strong axial stiffness, but little bending stiffness. The problem of cutting pattern is highly varied in their size, curvature and material stiffness. So, the approximation inherent in cooing pattern generation methods is quite different. Therefore the ordinary computer software of structural analysis & design is not suitable for membrane structures. In this study, we develop the program for cutting pattern generation using geodesic line, and investigate the result of example's cutting pattern in detail.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2004년도 춘계학술대회 논문집
• /
• pp.335-340
• /
• 2004

KS and ISO have proposed several evaluation methods of conventional machine tools. Even though the accuracy of the tools can be evaluated with those methods, there are still no proper evaluation methods of high speed machining. Because it is hard to evaluate characteristics of high speed machining such as decrease of cutting temperature, cutting force, and reduced machining time. Therefore, new evaluation method for high speed machine should be developed. In this paper, several shapes of model have been proposed to evaluate cutting accuracy of high speed machine.

• 한국공작기계학회논문집
• /
• 제14권5호
• /
• pp.7-12
• /
• 2005

This paper presents several time series methods to analyze the chatter mechanics by using the power spectrum of these algorithms considering the cutting dynamics. In this study, several time series models such as AR(burg, forwardbackward, geometric lattice, instrument variable, least square, Yule Walker), ARX(1s, iv4), ARMAX, ARMA, Box Jenkins, Output Error were modeled and compared with one another. Finally, it was proven that time series modelings are also a desirable and reliable algorithm than the other conventional methods(FFT) for the calculation of the chatter mode in turning operation. Also, the spectrum of times series methods is a little bit more powerful than the FFT fer the detection of a high noisy and weak chatter mode. The radial cutting force Fy has been used for spectrum and chatter stability lobe analysis in this study.

• 한국정밀공학회지
• /
• 제16권7호
• /
• pp.203-209
• /
• 1999

In this paper, we present the methods to predict the milled surface shapes in profile milling process. In the cutting process, tools are deflected due to the cutting forces varying with the imposed depth of cut and feedrate. Thus, the final shapes of the milled surface, generated by the nominal tool trajectory, are different from the required profile. In order to predict the milled surface shapes, we present two methods based on: (1) the deflected tool profile and (2) the trace of contact point between the tool and the workpiece. In the first method, we make an assumption that the milled surface corresponds to the deflected tool profile. In another method, we make we make an assumption that the milled surface is generated by the trace of the contact point between the cutting edge of the tool and workpiece. We present the surface generation process by calculating the trajectory of the contact points on the workpiece. Several simulations and experiments are performed to verify the proposed milled surface prediction methods.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.684-687
• /
• 2002

The authors have developed two devices which cuts the spend fuel rod to an optimal size and extracts fuel pellet from the pieces of cut fuel rods. These devices are so important to reduce radioactive wastes that some advanced countries developed their own methods and devices. The authors have benchmarked from these methods and devices. For spent fuel rod cutting, the tube cutting method has been chosen. some mechanical properties of the fuel tube and pellet has been carefully considered for an optimal cutting size. For fuel pellet extraction, a mechanically extracting method has been adopted. The existing chemical method have turned out to be inappropriate because it produced large amount of radioactive wastes, in spite of its high fuel recovery characteristics. The developed method has an advantage that it can be applied to other fuel rods that have different shapes and sizes. The two devices are set up and operated in the hot cell where people can not go in, so that the devices have been designed to be controlled remotely and modulated for easy maintenance. And the performance of the devices has been tested by using simulated fuel rod. From the experimental results, the devices are supposed to be useful for reducing radioactive wastes.

• 한국약용작물학회지
• /
• 제13권6호
• /
• pp.268-272
• /
• 2005

백수오 지주설치 생력화를 목적으로, 무지주 처리방법을 달리하여 백수오 중국도입종을 재배하고, 이에 따른 생육, 근수량 및 경영비를 검토한 결과를 요약하면 다음과 같다. 1. 관행 지주재배시 무지주 재배에 비해 생육이 양호한 경향이었으며, 무지주 처리 간에는 주만장과 주경의 총만장은 무처리, 적심, 선단예취 순으로 긴 반면, 경태는 선단예취, 적심, 무처리 순으로 굵었다. 선단예취시 엽수는 가장 적었으나 잎이 크고 엽당 무게가 무거운 편으로 이는 덩굴의 선단부 예취로 인해 수광면적이 확대됨으로써 광합성능률이 향상된 것으로 판단된다. 2. 지근의 수와 주근태는 지주재배와 선단예취에서 다소 많거나 굵었고, 주근장과 지근태는 지주재배와 적심 처리에서 길거나 굵었다. 3. 10a당 생근수량은 관행 지주재배시 1,918kg에 비해 무지주 재배시 $17.9{\sim}22.6%$ 감수되었으나, 지주생력화로 생산비가 감소됨으로써 경영비가 절감되어 소득이 $8%{\sim}17%$ 증가되었다. 무지주 처리방법 간에는 무처리에 비해 선단예취시 생근수량은 6%, 소득은 8% 각각 높았다.

• 한국잠사곤충학회지
• /
• 제28권2호
• /
• pp.9-14
• /
• 1986

고조삽목의 실용화를 위해, 삽상의 종류, 상토, 삽목시기, 발근촉진제의 효과, 삽목전처리, 삼수채취부위 등을 연구한 결과 다음과 같은 결과를 얻었다. 1. 삽목방법 중 활착률이 가장 높은 구는 사토에서 유합조직을 형성시킨 후 삽목하는 구였으며, 보온못자리구에서는 완전히 고사하여 가장 낮았다. 2. 삽목적기는 3월 26일로 이때에는 수상자, 사토상토를 제외하고 활착률 100%를 보였다. 3. 삽목채취 부위별 활착률은 상<중<하부 순으로 높았으나, 유합조직구에서는 중부에서 70-100%의 높은 활착률을 보였다. 4. 발근촉진제 Rootone-F 포도는 지조상·중부, 그리고 온상 20cm구에서 포도하지 않은 것보다 활착률을 높였으나, 다른 구에서는 뚜렷한 효과가 없었다. 5. 상토의 토성은 활착률에 일정한 경향을 보이지 않는다. 6. 삽목전 처리 중 3월 15일 채취, 빙고에 저장하였다가 삽목하거나, 유합조직의 형성후 삽목하는 경우 타처리에 비해 현저히 활착률이 높았으며, 채취후 방치하였다 삽목하는 전혀 활착되지 않았다.

• 대한기계학회논문집A
• /
• 제26권6호
• /
• pp.1053-1059
• /
• 2002

The purpose of this study is to suggest how the machining technique of constant control of cutting speed can improve precision machining and tool life in high speed machining using a ball end mill. Cutting speed is changed in machining fee form surfaces such as connecting rod die. So, we don't have supreme surface form and tool life on machining. To solve this problem we should settle on optimal cutting speeds in free form surface machining. And, to improve precision machining, We must execute high speed machining methods to output optimum NC data using developed constant control of cutting speed program after modeling by CAD/CAM. In this paper, a comparison was made of the cutting precision and tool life in conventional cutting and those in connecting rod machining applying the program developed.